/**
 * Expand a collapsed expand node by clicking its toggle button.
 *
 * This function finds the toggle button with aria-expanded="false" and programmatically
 * clicks it to expand the node. It does not wait for the expansion to complete.
 *
 * @param expandContainer - The expand container element.
 * @returns True if the toggle button was found and clicked, false otherwise.
 */
export declare const expandElement: (expandContainer: HTMLElement) => boolean;